This invention relates to electro-optical modules in general and more particularly to the type of electro-optical module which includes a housing and at least one electro-optical component, to whose optical active surface a connecting element that is insertable into a housing opening is capable of being optically coupled.
Electro-optical modules are understood, for example, to be the modules and, in particular, what are referred to as transceivers, for example, in the Siemens AG prospectus "Fiber Optic Components", issue EC 0291. These known electro-optical modules have a housing, in or on which at least one electro-optical component is retained. The electro-optical component can be a laser transmitting diode, for example, whose optical active surface--i.e., the output face of the light transmitted by the component--is capable of being optically coupled to a connecting element. For this purpose, the housing has an opening into which the connecting element is insertable. In addition or alternatively, the housing can also contain a component designed as a receiver, which converts light energy acting on its optical active surface into electrical signals.
So long as a connecting element has not been inserted into the housing opening and coupled to the electro-optical component, impurities can intrude into the housing and adversely affect the optical active surfaces; also light can unintentionally strike the active surface, so that, in such a case, a receiver would supply unwanted output signals. Electro-optical components, which are designed as high-energy light transmitters (e.g. laser diodes), pose a special danger, because the radiation they emit can do permanent damage, for example, to the eyes (especially to the retinas) of living beings. This danger is especially prevalent when the driving circuit for the transmitter is defective, as this results in a lasting or periodic uncontrolled transmission signal.
Therefore, there is a need to create an electro-optical module, whose electro-optical component(s) is or are protected from impurities and damage from the outside and/or where, when unconnected an unintentional incidence of light on the component or emergence of light from the component is reliably prevented.